GAMBIT Macros

Hello, I have some heat exchanger models that are stored in a file in a proprietary format. I want to convert this heat exchanger into a GAMBIT file to later run with Fluent. I wrote a c++ program that will spit out GAMBIT journal commands/code. Is there an efficient way of doing this ? In GAMBIT journal - how do I access a particular face of a brick ?

I did this before. You must record the macro from gambt first and generate the "journal file" line by line. Then you can replace some key numbers by variable name that can be replaced by a script (shell script).